Book ChapterDOI
[7] Mitochondrial respiratory control and the polarographic measurement of ADP : O ratios
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This chapter discusses the mitochondrial respiratory control and the polarographic measurement of ADP : O ratios and the principle of the oxygen electrode has been summarized, and the design of the vibrating oxygen electrode for use with speetrophotometric studies is illustrated.Abstract:
Publisher Summary This chapter discusses the mitochondrial respiratory control and the polarographic measurement of ADP : O ratios. The polarographic oxygen electrode technique is used for measuring rapid changes in the rate of oxygen utilization by cellular and subcellular systems. Although the polarographic method measures changes in oxygen concentration of photosynthetic systems, yeast cells, and nerve, but the oxygen electrode technique is applied to a study the mitochondrial respiration and oxidative phosphorytation. The principle of the oxygen electrode has been summarized, and the design of the vibrating oxygen electrode for use with speetrophotometric studies is illustrated. The oxygen electrode apparatus can be calibrated in a number of ways. A more accurate calibration of oxygen content can be obtained by gas equilibration with various nitrogen-oxygen mixtures. When tightly coupled mitochondria are suspended in an isotonic buffer, a slow rate of oxygen uptake is measured in the presence of substrate and absence of ADP. Addition of ADP causes an immediate increase in the rate of oxygen utilization. The concentration of oxygen utilized is proportional to the amount of ADP phosphorylated to ATP. The type of oxygen electrode tracings is presented from which an ADP : O ratio (equivalent to a P : O ratio) can be directly calculated.read more
Citations
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Complex III Releases Superoxide to Both Sides of the Inner Mitochondrial Membrane
TL;DR: It is demonstrated that Complex I-dependent superoxide is exclusively released into the matrix and that no detectable levels escape from intact mitochondria, fitting well with the proposed site of electron leak at Complex I.
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Biochemical properties of subsarcolemmal and interfibrillar mitochondria isolated from rat cardiac muscle.
TL;DR: Two populations of mitochondria were observed upon ultrastructural examination of cardiac muscle tissue, one located directly beneath the sarcolemma (subsarcolemmal mitochondria) and another between the myofibrils (interfibrillar mitochondria).
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Hyperoxia increases oxygen radical production in rat lungs and lung mitochondria.
Bruce A. Freeman,James D. Crapo +1 more
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Utilization of oxygen and reduced nicotinamide adenine dinucleotide phosphate by human placental microsomes during aromatization of androstenedione.
Thompson Ea,Siiteri Pk +1 more
TL;DR: It was determined that essentially all of the O2 consumed could be accounted for by accumulation of 19-hydroxyandrostenedione and 19-oxoandrosteningione and estrogens, suggesting that the final hydroxylation is the rate-limiting step in the aromatization of androstenedion.
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Cardiolipins and biomembrane function
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References
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Journal ArticleDOI
Continuous recording of blood oxygen tensions by polarography.
Journal ArticleDOI
Oxidative phosphorylations; rôle of inorganic phosphate and acceptor systems in control of metabolic rates.
Henry A. Lardy,Harlene Wellman +1 more
Journal ArticleDOI
A Simple and Rapid Assay of Oxidative Phosphorylation
Britton Chance,G. R. Williams +1 more
Journal ArticleDOI
Microelectrodes for measuring local oxygen tension in animal tissues
Philip W. Davies,Frank Brink +1 more
TL;DR: Two types of stationary platinum microelectrodes which electrolyze dissolved oxygen when suitable potentials are applied are described, which are possible to measure the oxygen tension in an open solution, and especially, to estimate local oxygen tensions in animal tissues.